General Notes. 141 



THE STATUS OF THE GENUS CENTRONYX BAIRD. 



The genus Centronyx was orfginally instituted by Professor Baird (Rep. 

 Explor. and Surv. R. R. Pac, IX, 1858, p. 440) for the reception of the 

 Baird sparrow, Emberiza bairdii Audubon. Mr. Ridgway in his "Birds of 

 North and Middle America" (Bull. U. S. Nat. Mus., I, 1901, p. 202) re- 

 diagnosed it as a distinct genus, but it has been currently regarded by 

 other authors as only subgenerically different from Ammodramus (= 

 Coturniculus). An examination of its characters, however, which we have 

 made in connection with the investigation of the affinities of allied groups, 

 seems to indicate that Mr. Ridgway's view of the generic distinctness of 

 Centronyx is entirely correct. It differs from Ammodramus in having four 

 instead of three primaries sinuated on the outer web; the claw of the hallux 

 not shorter than the hallux itself, and longer than the distance from the 

 anterior end of the nostril to the tip of the maxilla; the wing more than 

 six times the length of exposed culmen; and the tarsus not less than twice 

 the length of exposed culmen. Two characters, however, mentioned by 

 Mr. Ridgway, prove on examination of a series of specimens not to be en- 

 tirely constant; for the hallux is not always longer than the outer toe; 

 and the sixth primary, counting from the outermost, is not always ab- 

 ruptly shorter than the seventh. These, however, do not impair the 

 validity of the genus, as we have above shown. The only species referable 

 to Centronyx is its type, Centronyx bairdii (Audubon). 



— Harry C. Oberholser. 



THE GENERIC NAME OF THE ROOK. 



By some authors the rook, Corvus frugilegus Linnaeus, is placed in a 

 separate genus, by others retained in Corvus. When it has been generically 

 distinguished, Trypanocorax Kaup (Journ. f. Ornith., 1854, p. lv.; type, 

 Corvus frugilegus Linnaeus) has been usually employed as its generic name. 

 Dr. C. W. Richmond, however (Proc. U. S. Nat. Mus., LIII, August 16, 

 1917, p. 591), has rediscovered the original place of publication of the term 

 Frugilegus (Selys-Longchamps, Faune Beige, I, 1842, p. 68 [Lesson Ms.]; 

 type by monotypy and tautonymy, Corvus frugilegus Linnaeus) which 

 name, of course, is entirely pertinent, and of earlier date. 



A number of authors, and recently Dr. Ernst Hartert in particular, have 

 pointed out the important structural characteristics of this species, differ- 

 ences that clearly indicate its generic distinction. It differs from the typical 

 species of the genus Corvus in its relatively slender and more sharply 

 pointed bill (less so, however, than Heterocorax); short first primary 

 (counting from the outermost), which equals or is shorter than the ninth, 

 instead of being equal to the seventh; unfeathered, warty face in the adult; 

 absence of narial bristles, and thus entirely exposed nostrils, which condi- 

 tion, so far as we recall, is unique in the family Corvidae. 



In view of the above facts, the rook should be called Frugilegus fru- 

 gilegus (Linnaeus). — Harry C. Oberholser. 



